The problem is that when concurrent builds are enabled emails will not be sent until all the builds finish.

I have followed the issue and it stems from the fact that all builtin email notifications actions all have triggers which are dependent on previous builds so that they can know if the current build is 'still failing' or 'fixed' or 'broken' or 'still success' etc etc. This can be easily seen here.

I want to know how to send emails without waiting for other builds, via:

An existing plugin that can solve my problem.

Write or adapt my own email plugin.

A clever solution that I would never have thought of.

If I am to write or adapt my own email plugin, I would like to know if anyone has any experience with this, or a solution they might already have that they could share.